When you’re stalking barefoot runners, camouflage helps. “Some of them get kind of prancy when they notice you filming,” Peter Larson says. “They put on this notion of what they think barefoot running should be. It looks weird.” Larson, an evolutionary biologist at Saint Anselm College in New Hampshire who has been on the barefoot beat for two years now, is also a stickler about his timing. “You don’t want to catch them too early in a run, when they’re cold, or too late, when they’re tired.”

If everything comes together just right, you’ll be exactly where Larson was one Sunday morning in September: peeking out from behind a tree on Governors Island in New York Harbor, his digital video camera nearly invisible on an ankle-high tripod, as the Second Annual New York City Barefoot Run got under way about a quarter-mile up the road. Hundreds of runners — men and women, young and old, athletic and not so much so, natives from 11 different countries — came pattering down the asphalt straight toward his viewfinder.

About half of them were actually barefoot. The rest wore Vibram FiveFingers — a rubber foot glove with no heel cushion or arch support — or Spartacus-style sandals, or other superlight “minimalist” running shoes. Larson surreptitiously recorded them all, wondering how many (if any) had what he was looking for: the lost secret of perfect running.

It’s what Alberto Salazar, for a while the world’s dominant marathoner and now the coach of some of America’s top distance runners, describes in mythical-questing terms as the “one best way” — not the fastest, necessarily, but the best: an injury-proof, evolution-tested way to place one foot on the ground and pick it up before the other comes down. Left, right, repeat; that’s all running really is, a movement so natural that babies learn it the first time they rise to their feet. Yet sometime between childhood and adulthood — and between the dawn of our species and today — most of us lose the knack.

We were once the greatest endurance runners on earth. We didn’t have fangs, claws, strength or speed, but the springiness of our legs and our unrivaled ability to cool our bodies by sweating rather than panting enabled humans to chase prey until it dropped from heat exhaustion. Some speculate that collaboration on such hunts led to language, then shared technology. Running arguably made us the masters of the world.

So how did one of our greatest strengths become such a liability? “The data suggests up to 79 percent of all runners are injured every year,” says Stephen Messier, the director of the J. B. Snow Biomechanics Laboratory at Wake Forest University. “What’s more, those figures have been consistent since the 1970s.” Messier is currently 11 months into a study for the U.S. Army and estimates that 40 percent of his 200 subjects will be hurt within a year. “It’s become a serious public health crisis.”

Nothing seems able to check it: not cross-training, not stretching, not $400 custom-molded orthotics, not even softer surfaces. And those special running shoes everyone thinks he needs? In 40 years, no study has ever shown that they do anything to reduce injuries. On the contrary, the U.S. Army’s Public Health Command concluded in a report in 2010, drawing on three large-scale studies of thousands of military personnel, that using shoes tailored to individual foot shapes had “little influence on injuries.”

Two years ago, in my book, “Born to Run,” I suggested we don’t need smarter shoes; we need smarter feet. I’d gone into Mexico’s Copper Canyon to learn from the Tarahumara Indians, who tackle 100-mile races well into their geriatric years. I was a broken-down, middle-aged, ex-runner when I arrived. Nine months later, I was transformed. After getting rid of my cushioned shoes and adopting the Tarahumaras’ whisper-soft stride, I was able to join them for a 50-mile race through the canyons. I haven’t lost a day of running to injury since.

“Barefoot-style” shoes are now a $1.7 billion industry. But simply putting something different on your feet doesn’t make you a gliding Tarahumara. The “one best way” isn’t about footwear. It’s about form. Learn to run gently, and you can wear anything. Fail to do so, and no shoe — or lack of shoe — will make a difference.

That’s what Peter Larson discovered when he reviewed his footage after the New York City Barefoot Run. “It amazed me how many people in FiveFingers were still landing on their heels,” he says. They wanted to land lightly on their forefeet, or they wouldn’t be in FiveFingers, but there was a disconnect between their intentions and their actual movements. “Once we develop motor patterns, they’re very difficult to unlearn,” Larson explains. “Especially if you’re not sure what it’s supposed to feel like.”

The only way to halt the running-injury epidemic, it seems, is to find a simple, foolproof method to relearn what the Tarahumara never forgot. A one best way to the one best way.

Earlier this year, I may have found it. I was leafing through the back of an out-of-print book, a collection of runners’ biographies called “The Five Kings of Distance,” when I came across a three-page essay from 1908 titled “W. G. George’s Own Account From the 100-Up Exercise.” According to legend, this single drill turned a 16-year-old with almost no running experience into the foremost racer of his day.

I read George’s words: “By its constant practice and regular use alone, I have myself established many records on the running path and won more amateur track-championships than any other individual.” And it was safe, George said: the 100-Up is “incapable of harm when practiced discreetly.”

When I called Mark Cucuzzella to tell him about my find, he cut me off midsentence. “When can you get down here?” he demanded.

“Here” is Two Rivers Treads, a “natural” shoe store sandwiched between Maria’s Taqueria and German Street Coffee & Candlery in Shepherdstown, W.Va., which, against all odds, Cucuzzella has turned into possibly the country’s top learning center for the reinvention of running.

“What if people found out running can be totally fun no matter what kind of injuries they’ve had?” Cucuzzella said when I visited him last summer. “What if they could see — ” he jerked a thumb back toward his chest — “Exhibit A?”

Cucuzzella is a physician, a professor at West Virginia University’s Department of Family Medicine and an Air Force Reserve flight surgeon. Despite the demands of family life and multiple jobs, he still managed enough early-morning miles in his early 30s to routinely run marathons at a 5:30-per-mile pace. But he constantly battled injuries; at age 34, severe degenerative arthritis led to foot surgery. If he continued to run, his surgeon warned, the arthritis and pain would return.

Cucuzzella was despondent, until he began to wonder if there was some kind of furtive, Ninja way to run, as if you were sneaking up on someone. Cucuzzella threw himself into research and came across the work of, among others, Nicholas Romanov, a sports scientist in the former Soviet Union who developed a running technique he called the Pose Method. Romanov essentially had three rules: no cushioned shoes, no pushing off from the toes and, most of all, no landing on the heel.

Once Cucuzzella got used to this new style, it felt suspiciously easy, more like playful bouncing than serious running. As a test, he entered the Marine Corps Marathon. Six months after being told he should never run again, he finished in 2:28, just four minutes off his personal best.

“It was the beginning of a new life,” Cucuzzella told me. “I couldn’t believe that after a medical education and 20 years of running, so much of what I’d been taught about the body was being turned on its head.” Two weeks before turning 40, he won the Air Force Marathon and has since completed five other marathons under 2:35. Shortly before his 45th birthday this past September, he beat men half his age to win the Air Force Marathon again. He was running more on less training than 10 years before, but “felt fantastic.”

When he tried to spread the word, however, he encountered resistance. At a Runner’s World forum I attended before the Boston Marathon in April 2010, he told the story of how he bounced back from a lifetime of injuries by learning to run barefoot and relying on his legs’ natural shock absorption. Martyn Shorten, the former director of the Nike Sports Research Lab who now conducts tests on shoes up for review in Runner’s World, followed him to the microphone. “A physician talking about biomechanics — I guess I should talk about how to perform an appendectomy,” Shorten said. He then challenged Cucuzzella’s belief that cushioned shoes do more harm than good.

No matter. Cucuzzella went home and began hosting his own conferences. Peter Larson traveled from New Hampshire for Cucuzzella’s first gathering on a snowy weekend this past January. “I was a bit curious about how many people might show up to such an event in rural West Virginia,” Larson says. “Were the panelists going to outnumber the audience?” In fact, more than 150 attendees crowded right up to the dais.

Since then, West Virginia has become a destination for a growing number of those who are serious about the grass-roots reinvention of running. Galahad Clark, a seventh-generation shoemaker who created the Vivobarefoot line, flew in from London with the British running coach Lee Saxby for a one-day meeting with Cucuzzella. International researchers like Craig Richards, from Australia, and Hiro Tanaka, chairman of Exercise Physiology at the University of Fukuoka, have also visited, as well as scientists from a dozen different American states.

“He has turned a small town in an obese state into a running-crazed bastion of health,” Larson says. “Mark’s effort in transforming Shepherdstown is a testament to what a single person can accomplish.”

Not that he has everything figured out. I was at one of Cucuzzella’s free barefoot running clinics in May when he confronted his big problem: how do you actually teach this stuff? He had about 60 of us practicing drills on a grassy playground. “Now to run,” he said, “just bend forward from the ankles.” We all looked down at our ankles.

“No, no,” Cucuzzella said. “Posture, remember? Keep your heads up.”

We lifted our heads, and most of us then forgot to lean from the ankles. At that moment, a young girl flashed past us on her way to the monkey bars. Her back was straight, her head was high and her bare feet skittered along right under her hips.

“You mean like — ” someone said, pointing after the girl.

“Right,” Cucuzzella said. “Just watch her.”

So what ruined running for the rest of us who aren’t Tarahumara or 10 years old?

Back in the ’60s, Americans “ran way more and way faster in the thinnest little shoes, and we never got hurt,” Amby Burfoot, a longtime Runner’s World editor and former Boston Marathon champion, said during a talk before the Lehigh Valley Half-Marathon I attended last year. “I never even remember talking about injuries back then,” Burfoot said. “So you’ve got to wonder what’s changed.”

Bob Anderson knows at least one thing changed, because he watched it happen. As a high-school senior in 1966, he started Distance Running News, a twice-yearly magazine whose growth was so great that Anderson dropped out of college four years later to publish it full time as Runner’s World. Around then, another fledgling operation called Blue Ribbon Sports was pioneering cushioned running shoes; it became Nike. Together, the magazine and its biggest advertiser rode the running boom — until Anderson decided to see whether the shoes really worked.

“Some consumer advocate needed to test this stuff,” Anderson told me. He hired Peter Cavanagh, of the Penn State University biomechanics lab, to stress-test new products mechanically. “We tore the shoes apart,” Anderson says. He then graded shoes on a scale from zero to five stars and listed them from worst to first.

When a few of Nike’s shoes didn’t fare so well in the 1981 reviews, the company pulled its $1 million advertising contract with Runner’s World. Nike already had started its own magazine, Running, which would publish shoe reviews and commission star writers like Ken Kesey and Hunter S. Thompson.

“Nike would never advertise with me again,” Anderson says. “That hurt us bad.” In 1985, Anderson sold Runner’s World to Rodale, which, he says, promptly abolished his grading system. Today, every shoe in Runner’s World is effectively “recommended” for one kind of runner or another. David Willey, the magazine’s current editor, says that it only tests shoes that “are worth our while.” After Nike closed its magazine, it took its advertising back to Runner’s World. (Megan Saalfeld, a Nike spokeswoman, says she was unable to find someone to comment about this episode.)

“It’s a grading system where you can only get an A,” says Anderson, who went on to become the founder and chief executive of Ujena Swimwear.

Just as the shoe reviews were changing, so were the shoes: fear, the greatest of marketing tools, entered the game. Instead of being sold as performance accessories, running shoes were rebranded as safety items, like bike helmets and smoke alarms. Consumers were told they’d get hurt, perhaps for life, if they didn’t buy the “right” shoes. It was an audacious move that flew in the face of several biological truths: humans had thrived as running animals for two million years without corrective shoes, and asphalt was no harder than the traditional hunting terrains of the African savanna.

In 1985, Benno Nigg, founder and currently co-director of the University of Calgary’s Human Performance Lab, floated the notion that impact and rear-foot motion (called pronation) were dangerous. His work helped spur an arms race of experimental technology to counter those risks with plush heels and wedged shoes. Running magazines spread the new gospel. To this day, Runner’s World tells beginners that their first workout should be opening their wallets: “Go to a specialty running store . . . you’ll leave with a comfortable pair of shoes that will have you running pain- and injury-free.”

Nigg now believes mistakes were made. “Initial results were often overinterpreted and were partly responsible for a few ‘blunders’ in sport-shoe construction,” he said in a speech to the International Society of Biomechanics in 2005. The belief in the need for cushioning and pronation control, he told me, was, in retrospect, “completely wrong thinking.” His stance was seconded in June 2010, when The British Journal of Sports Medicine reported that a study of 105 women enrolled in a 13-week half-marathon training program found that every single runner who was given motion-control shoes to control excess foot pronation was injured. “You don’t need any protection at all except for cold and, like, gravel,” Nigg now says.

Of course, the only way to know what shoes have done to runners would be to travel back to a time when no one ever wore them. So that’s what one anthropologist has effectively done. In 2009, Daniel Lieberman, chairman of Harvard’s human evolutionary biology department, located a school in Kenya where no one wore shoes. Lieberman noticed something unusual: while most runners in shoes come down hard on their heels, these barefoot Kenyans tended to land softly on the balls of their feet.

Back at the lab, Lieberman found that barefoot runners land with almost zero initial impact shock. Heel-strikers, by comparison, collide with the ground with a force equal to as much as three times their body weight. “Most people today think barefoot running is dangerous and hurts, but actually you can run barefoot on the world’s hardest surfaces without the slightest discomfort and pain.”

Lieberman, who is 47 and a six-time marathoner, was so impressed by the results of his research that he began running barefoot himself. So has Irene Davis, director of Harvard Medical School’s Spaulding National Running Center. “I didn’t run myself for 30 years because of injuries,” Davis says. “I used to prescribe orthotics. Now, honest to God, I run 20 miles a week, and I haven’t had an injury since I started going barefoot.”

Last fall, at the end of a local 10-mile trail race, I surprised myself by finishing five minutes faster than I had four years ago, when I was in much better shape. I figured the result was a fluke — until it happened again. No special prep, awful travel schedule and yet a personal best in a six-mile race.

“I don’t get it,” I told Cucuzzella this past June when we went for a run together through the Shepherd University campus in Shepherdstown. “I’m four years older. I’m pretty sure I’m heavier. I’m not doing real workouts, just whatever I feel like each day. The only difference is I’ve been 100-Upping.”

It was five months since I discovered W.S. George’s “100-Up,” and I’d been doing the exercise regularly. In George’s essay, he says he invented the 100-Up in 1874, when he was an 16-year-old chemist’s apprentice in England and could train only during his lunch hour. By Year 2 of his experiment, the overworked lab assistant was the fastest amateur miler in England. By Year 5, he held world records in everything from the half-mile to 10 miles.

So is it possible that a 19th-century teenager succeeded where 21st-century technology has failed?

“Absolutely, yes,” says Steve Magness, a sports scientist who works with top Olympic prospects at Nike’s elite “Oregon Project.” He was hired by Alberto Salazar to create, essentially, a squad of anti-Salazars. Despite his domination of the marathon in the ’80s, Salazar was plagued with knee and hamstring problems. He was also a heel-striker, which he has described as “having a tire with a nail in it.” Magness’s brief is to find ways to teach Nike runners to run barefoot-style and puncture-proof their legs.

“From what you’re telling me, it sounds promising,” Magness told me. “I’d love to see it in action.”

Mark Cucuzzella was just as eager. “All right,” he said in the middle of our run. “Let’s get a look at this.” I snapped a twig and dropped the halves on the ground about eight inches apart to form targets for my landings. The 100-Up consists of two parts. For the “Minor,” you stand with both feet on the targets and your arms cocked in running position. “Now raise one knee to the height of the hip,” George writes, “bring the foot back and down again to its original position, touching the line lightly with the ball of the foot, and repeat with the other leg.”

That’s all there is to it. But it’s not so easy to hit your marks 100 times in a row while maintaining balance and proper knee height. Once you can, it’s on to the Major: “The body must be balanced on the ball of the foot, the heels being clear of the ground and the head and body being tilted very slightly forward. . . . Now, spring from the toe, bringing the knee to the level of the hip. . . . Repeat with the other leg and continue raising and lowering the legs alternately. This action is exactly that of running.”

Cucuzzella didn’t like it as a teaching method — he loved it. “It makes so much physiological and anatomical sense,” he said. “The key to injury-free running is balance, elasticity, stability in midstance and cadence. You’ve got all four right there.”

Cucuzzella began trying it himself. As I watched, I recalled another lone inventor, a Czechoslovakian soldier who dreamed up a similar drill: he’d throw dirty clothes in the bathtub with soap and water, then jog on top. You can’t heel strike or overstride on slippery laundry. There’s only one way to run in a tub: the one best way.

At the 1952 Olympics, Emil Zatopek became the only runner ever to win gold medals in all three distance events: 5,000 meters, 10,000 meters and the marathon, the first he ever ran. Granted, “the Human Locomotive” wasn’t a pretty sight. During his final push to the finish line, his head would loll and his arms would grab at the air “as if he’d just been stabbed through the heart,” as one sportswriter put it.

But from the waist down, Zatopek was always quick, light and springy, like a kid swooping across a playground — or like this once-arthritic physician in front of me, laughing with excitement as he hopped up and down in his bare feet in a parking lot.

Correction: November 20, 2011

A chart on Nov. 6 with an article about the correct way to run misstated the proper position of the elbow in relation to the opposite knee as it moves forward. The elbow should also move forward, not backward.